writing and reading from I2c eeprom ?

[RixtronixLAB]

Dear Members,

Where can I find from software development kit the example for writing and reading from I2C EEPROM ?

Thanks

[awneil]

An I2C EEPROM neither knows nor cares what microcontroller you use; all it sees is the transactions on the I2C bus - Start Conditions, Addressing, Stop Conditions; ACK/NAK, etc.

The Nordic SDK examples show you how to use the I2C (aka "TWI") hardware in the nRF52 - ie how to address a Slave, Read, and Write.

So you use the basic functions, together with the datasheet of your EEPROM, to generate the I2C transactions that the EEPROM requires.

For examples, see:

https://devzone.nordicsemi.com/f/nordic-q-a/70466/nrf52832-with-mpu9250-using-i2c-twi-on-sdk15-2-sd132-segger-embedded-studio/289159#289159

[RixtronixLAB]

There are 4 TWI examples

which one is the closest application with I2C EEPROM ?

This one

nRF5_SDK_17.0.2_d674dde\examples\peripheral\twi_master_with_twis_slave\pca10056\blank\arm5_no_packs ?

thanks

[RixtronixLAB]

on TWI scanner, I can not find 0xA0, which is 24C16, what do I miss ?

nfo> app: TWI scanner started.
                                               

nfo> app: TWI device detected at address 0x3C.
                               

nfo> app: TWI device detected at address 0x50.
                               

nfo> app: TWI device detected at address 0x51.
                               

nfo> app: TWI device detected at address 0x52.
                               

nfo> app: TWI device detected at address 0x53.
                               

nfo> app: TWI device detected at address 0x54.
                               

nfo> app: TWI device detected at address 0x55.
                               

nfo> app: TWI device detected at address 0x56.
                               

nfo> app: TWI device detected at address 0x57.
          

[RixtronixLAB]

do i need pull up resistor on SCL and SDA on 24C16 ? thanks

[RixtronixLAB]

How can I remove " escape sequences" ? thanks

[awneil]

You need pullups somewhere on the I2C bus - this is a basic requirement for any I2C bus.

[RixtronixLAB]

still can not see 24C16 address on TWI scanner, is my supply to low ? I checked, VCC=2.4V ?

[awneil]

Have you used an oscilloscope or analyser to see what's happening on the wires?

[RixtronixLAB]

Ok, I'll see with analyzer and posted, thanks

[RixtronixLAB]

I reckon, I have insufficient power for this 24C16 PU27, I will try with external 3.3V, I keep posted, thanks

[RixtronixLAB]

from this code,

err_code = eeprom_write(addr, &clear_val, 1);
if (NRF_SUCCESS != err_code)
{
NRF_LOG_INFO("communication error 24C16.\r\n");

return;
}

how can I print out err_code ?

NRF_LOG_INFO("%u",err_code); ?

[RixtronixLAB]

I got 

nfo> app: Error code 33281
   

what's the meaning ?